Because of their convenience, dispensing characteristics and aesthetics, liquid and/or gel detergent compositions are becoming an increasingly popular alternative to granular compositions among consumers. However, liquid and/or gel formulations often do not deliver the same effective performance as a granular composition.
To clean effectively, liquid/gel and granular detergent compositions contain chlorine bleach and have high alkalinity (i.e. silicate, carbonate and caustic). See, for example, U.S. Pat. No. 4,116,849, Leikhim, issued Sep. 26, 1978, U.S. Pat. No. 5,064,553, Dixit et al, issued Nov. 12, 1991 and U.S. Pat. No. 4,917,812, Cilley, issued Apr.17, 1990. Automatic dishwashing detergent compositions have been disclosed which use enzymes in place of chlorine bleach, for example, U.S. Pat. No. 4,162,987, Maguire et al, issued Jul. 31, 1979 and U.S. Pat. No. 4,101,457, Place et al, issued Jul. 18, 1978.
Liquid automatic dishwashing detergent compositions and processes have been disclosed to address the problems associated with rheology and other physical characteristics. See for example U.S. Pat. No. 5,075,027, Dixit et al, issued Dec. 24, 1991, U.S. Pat. No. 4,824,590, Roselle, issued Apr. 25, 1989, and U.S. Pat. No. 4,740,327, Julemont et al, issued Apr. 26, 1988.
It has been found that a viscoelastic, thixotropic, liquid, polymer-containing detergent composition can be formed with increased density, enhanced aesthetics and improved rheological efficiency of the polymer. Surprisingly, the simultaneous addition and mixing of a polymer slurry to a premix of detergent ingredients at moderate to high shear rate to neutralize and disperse the polymer, followed by deaeration of the resulting mixture yields a composition which has an increased density, enhanced aesthetics and a stable polymeric thixotropic thickener. Deaeration enhances aesthetics and increases the density of the composition. Simultaneously blending the polymer slurry with the premix at a high shear rate for a period sufficient to neutralize and disperse the polymer prevents undue rheodestruction of the polymeric thixotropic thickener.